September 28, 2025

What Is Buoyancy

Q: What is Archimedes' principle?

Archimedes' principle states that the buoyant force on a submerged object is equal to the weight of the fluid that the object displaces. If an object displaces a weight of water greater than its own weight, it will float.

Q: Does buoyancy only occur in water?

No, buoyancy occurs in any fluid, including gases. For example, a helium balloon floats because the buoyant force exerted by the surrounding air is greater than the weight of the balloon and the helium inside it.

Learn the definition of buoyancy, the upward force exerted by a fluid that opposes the weight of an immersed object. Understand why things float or sink.

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Defining Buoyancy

Buoyancy is the upward force that a fluid (a liquid or a gas) exerts on an object that is partially or fully submerged in it. This force acts in the opposite direction of gravity, pushing the object upward and making it feel lighter.

Example: Why a Boat Floats

A boat floats because the water it sits in pushes up on its hull with a buoyant force. This upward force is equal to the total weight of the boat pulling it down. As long as the buoyant force balances the boat's weight, the boat will float on the surface.

Frequently Asked Questions

What is Archimedes' principle?

Does buoyancy only occur in water?